A variety of flavorants have been developed and proposed for incorporation into tobacco products. Illustrative of such tobacco flavorants are those described in U.S. Pat. Nos. 3,580,259; 3,625,224; 3,722,516; 3,750,674; 3,879,425; 3,881,025; 3,884,247; 3,890,981; 3,903,900; 3,914,451; 3,915,175; 3,920,027; 3,924,644; 3,937,228; 3,943,943; 3,586,387: 4,379,754; and the like.
J. C. Leffingwell et al "Tobacco Flavoring For Smoking Products" (R. J. Reynolds publication, 1972) includes a listing of desirable flavorants for smoking compositions.
Of specific interest with respect to the present invention is the proposed utilization of lactone compounds as flavorants in tobacco products. Various lactones are known to contribute desirable properties to the flavor and aroma of tobacco products under smoking conditions.
U.S. Pat. No. 3,251,366 describes tobacco products that contain a lactone flavorant additive such as .alpha.,.beta.-dimethyl-.gamma.-pentyl-.gamma.-hydroxybutenolide which imparts a celery-like note to mainstream smoke.
U.S. Pat. No. 3,372,699 and U.S. Pat. No. 3,372,700 describe the use of a lactone such as .beta.-methylbutyrolactone or 4-hydroxy-4-methyl-5-hexenoic acid .gamma. lactone as a flavorant additive in tobacco products.
U.S. Pat. No. 3,380,457; U.S. Pat. No. 3,563,248; and U.S. Pat. No. 3,861,403 describe other lactones which are recommended for use as flavorant additives in tobacco products, such as .beta.-methyl-.delta.-valerolactone,
3-(2-hydroxycyclohexyl)propionic acid .delta. lactone, 4-methyl-6-n-pentyl-.alpha.-pyrone, and the like.
The high degree of volatility and ease of sublimation of flavorant additives such as aldehydes, ethers and lactones in tobacco products have presented problems in the manufacturing operations, and have resulted in a decreased shelf-life of the products due to losses of flavorant by evaporation on storage.
Recent developments have involved incorporating a low volatility organic additive to a 15 smoking composition, which under smoking conditions is pyrolyzed into one or more fragments that function to improve the taste and character of mainstream tobacco smoke, and in some cases a consequential improvement of sidestream smoke aroma.
U.S. Pat. No. 4,036,237 describes smoking compositions which contain an aromatic beta-hydroxy ester flavorant such as ethyl 2,2-dimethyl-3-hydroxy-3phenylpropionate, which pyrolyzes under smoking conditions to release benzaldehyde and ethyl isobutyrate flavorants.
U.S. Pat. No. 4,312,368 describes smoking compositions which contain a heterocyclic-hydroxy-substituted carboxylate flavorant-release additive such as ethyl 2-(2-butyl)-3-hydroxy-3-methyl-3-(3-pyridyl)propionate. Under smoking conditions this additive pyrolyzes into 3-acetylpyridine and ethyl .beta.-methylvalerate flavorants.
There is continuing research effort to develop improved smoking compositions which generate mainstream smoke with flavorant-enhanced taste and character under smoking conditions.
Accordingly, it is an object of this invention to provide smoking compositions having incorporated therein a flavorant component which is characterized by lack of mobility and/or volatility at ambient temperature.
It is another object of this invention to provide smoking compositions having incorporated therein a flavorant-release additive which under normal smoking conditions imparts improved flavor to mainstream smoke and improved aroma to sidestream smoke.
It is a further object of this invention to provide novel organic compounds which are adapted to be incorporated into cigarette fillers, and which under normal smoking conditions release volatile lactone and other flavorant constituents into cigarette smoke.
Other objects and advantages of the present invention shall become apparent from the following description and examples.